Engineered immune cell treatment for childhood leukaemia may be a step closer

Cancer Research UK

An immunotherapy treatment using genetically engineered cells has been used to successfully treat two infants with an aggressive kind of leukaemia, leaving them cancer free for over a year. 

Because the treatment used donor immune cells it is hoped this could be given to all suitable patients, rather than tailoring treatment to each individual. 

“So far this has only been tested with two patients, but more work is ongoing and we eagerly await the results” – Dr Steve Lee, University of Birmingham

The results, published in Science Translational Medicine, give an update on positive early findings for one of the children in 2015.

It reports that in both cases the treatment brought about remission within 4 weeks. Since then one child has been free of cancer for one year and the other child for 18 months. The children were 11 months and 16 months old at the time of treatment.

Both children received a transplant of so-called ‘universal’ immune cells engineered in the lab to target their cancer. It is thought that this is the first time this method has been tested in humans.

Experts believe the research is a step towards engineering immune cells so that one batch could be used to treat multiple patients, hopefully making this treatment more cost effective and readily available. 

“This study gives interesting and exciting early data suggesting that at least in some clinical settings this may be possible,” said Dr Steve Lee, an expert in immunology at the University of Birmingham and part-funded by Cancer Research UK. 

“So far this has only been tested with two patients, but more work is ongoing and we eagerly await the results.”

Both children had B cell acute lymphoblastic leukaemia (B-ALL), which is usually treated with a stem cell transplant. There are limited treatment options in patients younger than 1 year old.

Until now experimental immune cell engineering approaches have used the patient’s own immune cells to target the cancer. The cells are removed from the patient and engineered in the lab to produce what’s called a CAR T cell, before the cells are transfused back in to the patient. 

This approach is proving very effective for treating some blood cancers, said Lee. But he added that engineering cells on a patient-by-patient basis is expensive, difficult and time-consuming.

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There may also be times when using the patient’s own cells isn’t possible. This might be the case “if the patient has a very run-down immune system because of their disease or previous treatments”. 

The challenge in addressing this has been that transplanting cells from a donor involves introducing ‘foreign’ cells into the body. This risks them being rejected by the patient before they can attack the cancer, or more seriously, the new cells can attack the patient’s healthy tissue. 

But the cells used to treat the two children in the latest study had specific genes edited to reduce these risks.

The technique isn’t yet perfected as one child developed a condition called graft-versus-host disease, where the transplanted cells attack the patient’s body. But this was resolved with other treatment.

References

Qasim, W. (2017). Molecular remission of infant B-ALL after infusion of universal TALEN gene-edited CAR T cells. Sci. Translat. Med. (9) 374. DOI: 10.1126/scitranslmed.aaj201